No, this is not a reference to Brave New World, but to something that turned up in my FB feed this morning, concerning ways of getting cash away from the sticky fingers of shop assistants.Some ran on wires, others ran through tubes, and as a small boy, these things made me aware that sometimes, rarely, Heath Robinson gadgets might work.
At the age of 8, I tried making Meccano versions of the run-on-wires models, without success. I knew about the pneumatic versions, but the Meccano sets had inconvenient holes, so I gave up.
In what follows, the pics are more detailed than they appear here: click on them to see them in all their glory.
As it happens, I wrote about such things in my Not Your Usual Clever Ideas, available on Kindle (it includes shoe guns, sharkproof suits and pile drivers powered by gunpowder and the 'rowing bike' seen on the left), but here's the detail on the stranger ways that things were moved by air pressure.In 1868, all eyes were upon the new device, the pneumatic telegraph, which was going to revolutionise the world by allowing one to send actual documents hurtling to their destination. This was the pneumatic telegraph, which was all the rage in the 1860s.
The Pneumatic Dispatch Company in London declared its hand
in 1861, when they set up a quarter of a mile (400 metres) of test tubing at
Battersea, near the Victoria railway bridge. This included irregular curves and
gradients to show that the terrain would be no obstacle to a working system.
Carriages were introduced and air was drawn out in front of them to give a
pressure differential of "seven to eleven inches of water".
Atmospheric pressure is taken today as 100 kilopascals,
and it supports about 400 inches of water, so we are talking here of a pressure
in the 2-3 kilopascal range, about the same difference as that between the top
and bottom of a 300-metre building, so not that great. Still, this gentle
difference was enough to accelerate the rail cars to 25 mph (40 km/hr), and the
individual cast iron tubes were 9 feet (2.7 metres) long and about 850 mm high.
There was no seal, which would have caused frictional
loss, so there was a small amount of "windage", and most importantly,
Parliament had granted them the power to "open the streets", to lay
the tubes that would no doubt soon link all of the post offices in the world's
greatest metropolis.
By 1862, the company was meeting to vote on an increase
in capital to fund extended works and to obtain new machinery, and a further
£50 000 was subscribed, though several members opposed the motion, one of them
declaring the system a financial failure which ought to abandoned. The details
of the company are not very clear, but a 1929 enquiry mentioned "the Post
Office Tunnel", constructed by the company in 1866, and found to be less
than air-tight. The Post Office bought it in 1921, and the tunnel ended its
days as a conduit for telephone cables.
By 1863, 110 mails passed through the pneumatic despatch
tube from the station to the district post-office during each day, and, said a
report in Scientific American, the
occasional human was allowed to ride in the carts.
For some years, the system was used to carry parcels from
the railway to the Post Office. In the USA, though, there were far more
ambitious plans. By 1867, these extended to mail sorting systems that would
carry letters in scurrying carts, hither and thither, under the streets of
American cities.
That was nothing, though, to the grand plans of the
Waterloos and Whitehall Pneumatic Railway Company which planned to send parcels
under the Thames in a giant tube, 12 feet 9 inches (3.9 metres) in diameter.
This would connect the various lines which were by then operating on either
side of the river. The illustration shows sections of the tube being prepared
on dry land before being lowered into the river.
The tube systems operated successfully in a few cities,
but they had their greatest penetration in stores, where trusted cashiers,
locked in cages, received cash and dockets by pneumatic tube, and sent receipts
and change back, again by tube, to be handed to the customer.
If you want the original images, here are the sources.
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